Numerous oscillator circuits have been designed with the capability of providing controlled output frequency variation within a given range. To produce these frequency variations obviously requires some variation of circuit parameters and usually involves some variation in circuit capacitance. The prior art includes a system for digitally correcting an oscillator frequency by first converting the digital information to an analog voltage which is applied to a varactor diode. Any changes in digital code changes the analog voltage and varies the varactor capacitance which, in turn, changes the oscillator frequency. In this type of system, it is difficult to achieve a very small change in capacitance in the varactor capacitance to achieve a very small deviation in oscillator frequency without complex circuitry because very small voltage changes are required to produce these small variations in capacitance and these small variations in voltages are in the noise level of the diode. Further, the changes in capacitance are non-linear with respect to variations in applied voltages. Other systems involve digitally or manually switching in various combinations of capacitors that are made available in the form of a bank of capacitors. For the digitally switched systems that include a bank of capacitors, very small changes in capacitance are difficult to achieve because of the physical limitations related to the capacitors that may be employed. The smallest lumped constant capacitor is typically in the order of 0.1 pf. Tolerance, physical size, and cost may present substantial problems depending on the required system parameters. Further, each capacitor in the bank must be physically connected into the system by different leads, each having a different stray capacitance which changes with environment. In addition to the problems associated with the digitally switched systems, the mechanically switched systems have failure problems traditionally associated with switches, especially those which are miniature. Thus, the prior art is only capable of easily achieving predictable and stable variations in capacitance which are relatively large in order to produce, for instance, relatively large changes in oscillator frequency.